Polarization imaging apparatus, polarization imaging method, controller and storage medium

Patent metadata

Field	Value
Publication number	US-11579474-B2
Application number	US-202017255438-A
Country	US
Kind code	B2
Filing date	May 26, 2020
Priority date	Jun 6, 2019
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

Provided are a polarization imaging apparatus, a polarization imaging method, a controller and a computer readable storage medium. The polarization imaging apparatus includes an optical rotation device, a lens device, an image sensor, an image processor, and a controller which are sequentially arranged along a ray direction of incident light. The controller is configured to control the optical rotation device to be in a first optical rotation state or a second optical rotation state, control the lens device to be in an in-focus state or an out-of-focus state, and control the image sensor to collect light passing through the optical rotation device and the lens device to obtain multiple images. The image processor is configured to obtain polarized image information according to the multiple images.

First claim

What we claim is:

1. A polarization imaging apparatus, comprising an optical rotation device, a lens device, an image sensor, an image processor, and a controller which are sequentially arranged along a ray direction of incident light, wherein,
the controller is connected with the optical rotation device, the lens device, and the image sensor respectively, and is configured to control the optical rotation device to be in a first optical rotation state or a second optical rotation state, control the lens device to be in an in-focus state or an out-of-focus state, and control the image sensor to collect light passing through the optical rotation device and the lens device to obtain a plurality of images; wherein a difference between an optical rotation angle of the second optical rotation state and an optical rotation angle of the first optical rotation state is equal to 90 degrees;
the image processor is connected with the image sensor and is configured to obtain polarized image information according to the plurality of images,
wherein the plurality of images comprise:
an original image obtained by the image sensor when the optical rotation device is in the second optical rotation state and the lens device is in the out-of-focus state;
a second image obtained by the image sensor when the optical rotation device is in the second optical rotation state and the lens device is in the in-focus state; and
a first image obtained by the image sensor when the optical rotation device is in the first optical rotation state and the lens device is in the in-focus state.

2. The polarization imaging apparatus according to claim 1 , wherein,
the optical rotation device comprises a twist nematic liquid crystal cell; when the twist nematic liquid crystal cell is in the first optical rotation state, a polarization direction of light passing through the twist nematic liquid crystal cell is not rotated, and when the twist nematic liquid crystal cell is in the second optical rotation state, a polarization direction of light passing through the twist nematic liquid crystal cell is rotated by 90 degrees.

3. The polarization imaging apparatus according to claim 1 , wherein,
the lens device comprises a liquid crystal lens, or comprises a liquid crystal lens and a glass lens; when the liquid crystal lens is in the out-of-focus state, light passing through the liquid crystal lens is not modulated, and when the liquid crystal lens is in the in-focus state, a polarization component, in a set direction, of light passing through the liquid crystal lens is modulated.

4. The polarization imaging apparatus according to claim 2 , wherein,
the controller comprises a twist nematic liquid crystal driving circuit, a first control circuit, and a third control circuit, wherein:
the twist nematic liquid crystal driving circuit is connected with the twist nematic liquid crystal cell and the first control circuit respectively, and is configured to control the twist nematic liquid crystal cell to be in the first or second optical rotation state according to a control instruction sent by the first control circuit;
the first control circuit is connected with the twist nematic liquid crystal driving circuit, and is configured to control the twist nematic liquid crystal driving circuit by sending a control signal; and
the third control circuit is connected with the image sensor, and is configured to control the image sensor by sending a control signal.

5. The polarization imaging apparatus according to claim 3 , wherein,
the controller comprises a liquid crystal lens driving circuit, a second control circuit, and a third control circuit, wherein:
the liquid crystal lens driving circuit is connected with the liquid crystal lens and the second control circuit respectively, and is configured to control the liquid crystal lens to be in the in-focus state or the out-of-focus state according to a control instruction sent by the second control circuit;
the second control circuit is connected with the liquid crystal lens driving circuit, and is configured to control the liquid crystal lens driving circuit by sending a control signal; and
the third control circuit is connected with the image sensor, and is configured to control the image sensor by sending a control signal.

6. The polarization imaging apparatus according to claim 1 , wherein, the polarized image information comprises one or more of the following information: a polarized image in a first direction, a polarized image in a second direction, a complete polarized image, and a difference between the polarized image in the first direction and the polarized image in the second direction, wherein the first direction is perpendicular to the second direction; wherein,
the polarized image in the first direction=a first image−an original image;
the polarized image in the second direction=a second image−the original image;
the complete polarized image=a result of subtracting the original image from the first image+a result of subtracting the original image from the second image;
the difference between the polarized image in the first direction and the polarized image in the second direction=the first image−the second image.

7. A polarization imaging method, wherein an optical rotation device, a lens device and an image sensor are sequentially arranged along a ray direction of incident light, and the method comprises:
controlling the optical rotation device to be in a first optical rotation state or a second optical rotation state, controlling the lens device to be in an in-focus state or an out-of-focus state, and controlling the image sensor to collect light passing through the optical rotation device and the lens device to obtain a plurality of images; wherein a difference between an optical rotation angle of the second optical rotation state and an optical rotation angle of the first optical rotation state is equal to 90 degrees; and
obtaining polarized image information according to the plurality of images,
wherein the plurality of images comprise:
an original image obtained by the image sensor when the optical rotation device is in the second optical rotation state and the lens device is in the out-of-focus state;
a second image obtained by the image sensor when the optical rotation device is in the second optical rotation state and the lens device is in the in-focus state; and
a first image obtained by the image sensor when the optical rotation device is in the first optical rotation state and the lens device is in the in-focus state.

8. The polarization imaging method according to claim 7 , wherein,
the optical rotation device comprises a twist nematic liquid crystal cell; when the twist nematic liquid crystal cell is controlled to be in the first optical rotation state, a polarization direction of light passing through the twist nematic liquid crystal cell is not rotated, and when the twist nematic liquid crystal cell is controlled to be in the second optical rotation state, a polarization direction of light passing through the twist nematic liquid crystal cell is rotated by 90 degrees.

9. The polarization imaging method according to claim 7 , wherein,
the lens device comprises a liquid crystal lens, or comprises a liquid crystal lens and a glass lens; when the liquid crystal lens is controlled to be in the out-of-focus state, light passing through the liquid crystal lens is not modulated, and when the liquid crystal lens is controlled to be in the in-focus state, a polarization component, in a set direction, of light passing through the liquid crystal lens is modulated.

10. The polarization imaging method according to claim 7 , wherein, controlling the optical rotation device to be in

Assignees

• Boe Technology Group Co Ltd
• Univ Electronic Sci & Tech China

Inventors

• Chen Xiaoxi
• Zhang Junrui
• Ye Mao
• Zhu Xuehui
• Wang Zhidong
• Li Pengwei
• Zhou Lijia

Classifications

• G02F1/1396

  the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell (G02F1/141 takes precedence) · CPC title

• G02F1/29

  for the control of the position or the direction of light beams, i.e. deflection · CPC title

• G02F1/0136 Primary

  for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation (G02F1/0353 takes precedence) · CPC title

• H04N23/60

  Control of cameras or camera modules · CPC title

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title